Why: Common and safe exercises for the lower back. While many exercises are advocated the majority of these are chosen because they train the trunk (i.e. core) musculature without imparting excessive stress on the spine
The Key: A commonality across these exercises is that the spine stays in neutral. There is no extension or flexion or twisting during most of these exercises.
Pictures can also be seen at McGill’s Big Three post (click here) and here for the SI Joint)